SARS-CoV N

The SARS coronavirus, sometimes shortened to SARS-CoV, is the virus that causes severe acute respiratory syndrome (SARS). SARS coronavirus is a positive and single stranded RNA virus belonging to a family of enveloped coronaviruses. Its genome is about 29.7kb, which is one of the largest among RNA viruses. The SARS virus has 13 known genes and 14 known proteins. There are 265 nucleotides in the 5'UTR and 342 nucleotides in the 3'UTR. SARS is similar to other coronaviruses in that its genome expression starts with translation of two large ORFs, 1a and 1b, both of which are polyproteins. The functions of several of these proteins are known: ORFs 1a and 1b encode the replicase and there are four major structural proteins: nucleocapsid, spike, membrane and envelope. It also encodes for eight unique proteins, known as the accessory proteins, all with no known homologues. Nucleocapsid proteins of other coronavirus have been reported to be involved in forming the viral core and also in the packaging and transcription of the viral RNA.

SARS coronavirus nucleocapsid protein

Packages the positive strand viral genome RNA into a helical ribonucleocapsid (RNP) and plays a fundamental role during virion assembly through its interactions with the viral genome and membrane protein M. Plays an important role in enhancing the efficiency of subgenomic viral RNA transcription as well as viral replication (PubMed:17210170).
May modulate transforming growth factor-beta signaling by binding host SMAD3 (PubMed:18055455).

Viral RNA genome packaging

Virion
Host endoplasmic reticulum-Golgi intermediate compartment
Host Golgi apparatus
Host cytoplasm, host perinuclear region
Located inside the virion, complexed with the viral RNA. Probably associates with ER-derived membranes where it participates in viral RNA synthesis and virus budding.

ADP-ribosylated. The ADP-ribosylation is retained in the virion during infection.
Phosphorylated on serine and threonine residues (By similarity).
Phosphorylated by host GSK3A and GSK3B. Phosphorylation allows recruitment of host RNA helicase DDX1 which facilitates template readthrough and enables longer subgenomic mRNA synthesis